a is the lower parallel base,
b is the upper parallel base,
c is the left leg and
d is the right leg.
e runs from the lower-left to the upper-right corner;
f runs from the lower-right to the upper-left corner.
h is the perpendicular height
x is the signed horizontal offset from the lower-left corner to the perpendicular projection of the upper-left corner.
A positive x is to the right; a negative x is to the left.
This trapezoid calculator can be used whenever some dimensions of a trapezoid are known and the remaining measurements need to be determined. It is useful for geometry problems, checking calculations, construction and design work, estimating material dimensions, and general educational use.
Enter as many known measurements as you have. All length values must use the same unit; area is then in that unit squared, for example, if your inputs are in metres, the output for area will be in square metres ( m2).
Some combinations of measurements may not uniquely define a trapezoid, in which case only dimensions that can be determined unambiguously will be shown.
Enter whatever values are known, using either the digits 0-9 or numbers as words, e.g. "Ninety-Nine", then click the 'Calculate' button.
Leave unknown values blank - this tool will calculate as many as the data allows.